Heat exchange unit



Sept. ll, 1951 R. w. KRITZERA HEAT EXCHANGE UNIT 2 Sheets-Sheet 1 Filed Feb. 14, 1947 Sept. ll, 1951 R. w. KRlTzER 2,567,716

HEAT EXCHANGE UNIT Filed Feb. 14, 1947 2 Sheeis-Sheet 2 Jig@ P ummm Patented Sept. 11`, 1951 UNITED sTATEs PATENT oEFlcE 2,567,716 HEAT EXCHANGE UNrr Richard W. Kritzer, Chicago. Ill.

Application February 14, 1947, Serial No. 728,579

6 Claims.

The invention relates to heat exchange units of the type which includes a coil for conducting fluid and wall-forming plates conductively connected I to the coil.

of this type whereby the coil and plates can be expeditiously assembled for eillcient heat conduction between them.

Another o bject of the invention is to provide an improved method of fabricating heat exchange units which include a coil for conducting a fluid and wall-forming plates conductively connected thereto at both sides of the coil.

Another object of the invention is to provide a heat exchange unit of said type, which includes wall-forming plates provided with flanges and a coil of pipe extending through and secured in said flanges and provided with flat portions contiguous to the plates, for eillcient heat Vconduction.

Other objects of the invention will appear from the detailed description.

'I'he invention consists in the several novel features hereinafter set forth, and more particularly defined by claims at the conclusion hereof.

In the drawings:

Fig. 1 is a perspective view of a heat ex-change 'unit which includes wall-forming plates at both sides of a coil and embodying the invention, parts being broken away for illustrative purposes.

Fig. 2 is a section taken on line 2--2 of Fig. l.

Fig. 3 is a section illustrating the coil and plates arranged together preparatory to deformation of the coil in a press, for ilxedly assembling the coil and the plates.

Fig. 4 is a similar section illustrating the coil deformed and flattened by pressure applied through the plates.

Fig. 5 is a perspective view on an enlarged scale, illustrating one of the apertures in the flange of one of the plates.

Fig. 6 is a perspective view exemplifying the invention in a heat exchange unit of the single wall type.

Fig. 7 is a section illustrating the assembly of the coil and plates of the single wall type, preparatory to the flattening of the coil.

Fig. 8 is a section illustrating the manner of flattening the coil in the single wall type of unit l.to flxedly assemble the coil and plates at one side of the coil.

The invention is exemplified (Figs. 1 to 5) in a heat exchange unit which comprises a coil of pipe between series of plates which form walls or outer faces of the unit for heat conduction to a chambei` in which the unit is installed; for example: a freezingA chamber or a deep `freeze installation. The coil forms a conduit through which flows fluid such, for example, as a refrigerant, and comprises substantially parallel members I5, bends I6 serially connecting said members, and inlet and outlet terminals i1 and It on the ends of the coil, respectively. This coil is initially circular in cross-section and expanded in apertures in flanges on the plates. The plate structure of the unit is composed of a series of flat face plates 20, which form a wall and have their inner faces contiguous to one side of the coil, and a series of plates 2|, which form a wall and are contiguous to the other side of the coil. Plates 20 are provided with inwardly extending integral flanges 22, which extend -crosswise of the parallel members of the coil, and plates 2| are provided with similar integral flanges 23. The side-faces of the flanges of each series of plates are in abutting relation and the parallel members of the coil extend through the flangesof both series of plates. The flanges of each series of plates extend across the space in which the coil is placed, and have their edges abutting the inner faces of the plates of the opposite series.

Flanges 22 of plates 20 and flanges 23 of plates l 2|, are provided with apertures 29 through which the parallel members l5 of the coil extend. Each aperture intersects the edge of the flange, is constricted at said edge as at 30, and extends across the flange from its edge to the junction of the flange and plate. The coil, while it is circular in cross-section, is inserted into the apertures and when the coil is cross-sectionally deformed to conform to the contour of the aperture, Willbe flxedly secured in the flanges, against withdrawal from the apertures. e Each aperture has oppositely disposed curved edge portions 3| inwardly of the constriction 30, and the wall of the coil is cross-sectionally expanded as hereinafter described, to produce a tight grip between the wall of the coil and the edges of the apertures. The coil has a flattened portion 32 on one of its sides, which is coplanar and firmly contacts with the inner face of plates 20, and has a flattened portion 33 on its opposite side which is coplanar and contacts with the inner face of plates 2 I'. In this construction, the tight grip between the outer periphery of the coil and the edges of the apertures 29 and the extended area provided by the fiattened portions on the opposite sides of the coil and the at inner faces of the plates, provide for efficient heat conduction between the coil and the plates. The cross-sectional deformation of the wall of the coil, expands it in the apertures in the flanges and forms the flat portions of. the coil to conform to and contact with, the inner faces of the oppositely disposed plates. Channel strips 25 for enclosing the ends of the space between the opposite side plates, are secured to the end plates by screws 26. The connecting bends I6 of the coil are disposed between the plates which form the end portions of the plate structure.

In the fabrication of these heat exchange units, a length of tubing substantially circular in crosssection, is first bent or preformed to provide longitudinal or parallel members I5 and the connectlng bends I6 in the coil. Plates 20 and 2| while flat, are punched along their margins. to

3 provide apertures 29 which intersect the edges of the plates and are spaced apart along the flanges, to receive the parallel members l5 of the coil. Next, plates '20 and 2| are bent along parallel lines to form the flanges 22 and 23, so that the apertures 29 will extend inwardly from the edges of the flanges to the inner face of the plates. The constrieted open ends of the apertures at the edges of the flanges. are of sufficient width to permit the coil members while circular in cross-section, to be placed in the apertures with one side of the coil engaging the inner faces of one series of the plates. The diameter of the coil while it is circular, is greater than the crosswidth of the flanges, so that when it is rst inserted in the apertures, one side portion of the coil protrudes above the edges of the flanges while the opposite side portion rests on the inner face of the plates. The longitudinal width at the curved edges 3| of the apertures between the constricted open end and the plates, is of greater width than the open ends of the apertures. for expansion of the coil to form an interlock between the coil and the flanges. The plates of one series, are placed side by side on the bed a of a suitable press. The parallel members l5 and connecting bends I6 of the coil while tubular in cross-section, are then placed in the series of plates on said bed with the parallel members i5 in the apertures in the flanges 22 of said plates, as illustrated in Fig. 3. Next, the series of plates 2| for forming the opposite wall of the unit, are placed in contiguous relation and on the coil with the inner faces of said plates resting on the protruding side of the coil, and 2 with apertures 29 in flanges 23 around members |5. The series of plates 2|) will then be supported on the bed a. of the press, the coil will be supported on plates 20 and plates 2'| will rest on the protruding opposite side of the coil. Nexti an upper press member b is operated to exert pressure against the outer faces of both series of plates with the coil between them, until the flanges of the plates on each side of the coil engage the inner faces of the plates of the opposite side. The coil will thereby be deformed to provide flat areas I9 at both of its sides which will be coplanar with and pressed against the inner faces of the plates, and the wall of the coil will be expanded in the apertures 29 longitudinally of the flanges, to'force the opposite portions thereof, into tightly gripping relation with the curved edges 3| of the apertures. This single press operation will fixedly assemble the coil and wall-forming plates of the unit. The portions of the coil which extend to the outside of the plate structure, are circular in cross-section. for connection to pipes for conducting fluid to and from the coil. After the coil and plates 23 and 2| have been thus fixedly assembled, channel plates are secured to the open ends of the plates 20 and 2|.

In this heat exchanger and its method of fabrication, the coil forming the tubing is deformed and interlocked with the flanges of both of the series of plates forming both side faces of the exchanger, and the tubing is flattened to provide extended areas for heat transfer between the coil and the inner faces of the plates and between the coil and the flanges which are for heat conduction to the plates.

In F.gs. 6 to 8, the invention is exemplified in a heat exchanger which comprises a coil including parallel courses and connecting bends and plates for forming a Wall at one side of the coil,

and including integral flanges in which the coil is interlocked. The coil, in this form of the invention, is initially circular in cross-section. and is provided with parallel members and connecting bends and inlet and outlet terminals. as previously described. The wall-forming structure comprises a series of plates 40 provided with integral flanges 4| which extend crosswise of the coil.A The plates 40 are provided with integral flanges 4| having faces in abutting relation. Indented interfltting portions 43 hold together and spot the plates 40 in aligned relation. The flanges 4| are provided with apertures 29", which break through said flanges and are of the contour previously described, having curved edge portions 44 and a constricted open end 42 at the edges of the flanges, to provide a gap of sufficient width to permit the coil while it is circular in cross-section, to pass into the apertures and engage the inner face of plates 40. In fabricating this unit, the plates 40 with their flanges 4| upstanding, are placed in assembled relation on bed a of the press. The coil which is preformed with the parallel members and con- I necting bends, is then laid into the apertures 29L in flanges 4|, as illustrated in Fig. '7. Relative movement is then imparted to the press members a and b, and all portions of the coil within the plate structure are deformed cross-sectionally, to form flat areas 45 on opposite sides of the coil. The flat areas 45 at one side of the coil. conform to and are coplanar with, the inner faces of plates 40, and the fiat areas 45 at the opposite side of the coil, are substantially coplanar or flush with, the edges of flanges 4|. The flattening of the coil expands it cross-sectionally across the apertures 29a, to form an interlock and to cause the outer periphery of the coil to be in tightly fitting relation with the edges of the apertures 29a, and the flattened portions at one side of the coil to be in contact with the inner faces of the plates. This construction provides for efficient heat conduction between the coil and the plate structure which forms a single wall of the unit. This form of the invention exemplifies a simple and efficient method for fabricating heat exchange units which include a coil and plates forming a single wall structure combined therewith, for heat conduction.

The invention exemplifies a heat exchange unit which comprises a coil of tubing for conducting a, fluid and a plate structure forming a single or double wall which is joined to the coil, for eilicient heat conduction. It also exemplifies a heat exchange unit which includes a coil for conducting fluid and plates forming a single or double wall. which are provided with integral flanges in which the members of the coil are interlocked and provided with flat areas conforming to and coplanar with, the inner.. faces of the plates, for efficient heat conduction.

The invention is not to be understood as limited to the details described, since these may be modified within the scope of the appended claims without departing from the spirit or scope of the invention.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

1. That improvement in fabricating doublewall heat exchange units embodying plates provided with integral wall-forming face-portions and marginal fin-forming flanges, and a coil for conducting fluid, which comprises: preforming tubing of a greater diameter than the width of the anges into a coil, cutting in the flanges,

apertures for receiving the coil sidewise, with constricted portions at the outer edges of the flanges, assembling two series of the plates with their flanges extending inwardly and their face-portions substantially coplanar on opposite sides of the unit to form walls and the flanges in abutting relation, and with the coil in the apertures of the flanges of both series of plates, and pressing together opposite face portions of the plates and deforming the coil to expand it in the aperture of the anges of both series for interlock with the edges of the apertures and simultaneously flattening portions of the coil to t the inner faces of both series of plates, and thereby producing a unitary structure with the face-portions of the plates forming the substantially continuous double-wall with integral fins and with the coil permanently attached to the plates.

2. That improvement in fabricating double-wall heat exchange units embodying plates provided with integral wall-forming face-portions and marginal fin-forming fianges, and a coil for conducting fluid, which comprises: preforming tubing oi' a greater diameter than the width of the anges into a coil, cutting in the flanges, apertures for receiving the coil sidewise, extending substantially across the flanges, and with constricted portions at the outer edges of the flanges, assembling two series of the plates with their flanges extending inwardly and their face-portions substantially coplanar on opposite sides of the unit to form walls and the flanges in abutting relation, and with the coil in the apertures of the flanges of both series of plates, and pressing together opposite face portions of the plates and deforming the coil to expand it in the apertures o1' the flanges of both series for interlock with the edges of the apertures and simultaneously flattening the coil against the inner faces of the face-portions and thereby producing a unitary structure with the face-portions of the plates forming the substantially continuous double-wall with integral fins and with the coil permanently attached to the plates.

3. A heat exchange unit, comprising a coil for conducting fluid, including substantially parallel members and connecting bends, two series of plates, each -plate including a face-portion and integral marginal flanges for providing fins on the coil, the face-portions of the series of plates forming walls at the opposite sides of the coil, the flanges of each series being extended to the inner faces of the face-portions on the opposite series, the fianges having open-sided apertures, with constricted portions at the outer edges of the flanges, the coil having a cross-sectional contour in tightly gripped relation with the edges, and interlocked with the edges of the constricted portions of the apertures, by which the plates are permanently secured on the coil, with the faceportions forming the walls and the flanges secured to form ns on the coil.

4. A heat exchange unit, comprising a coil for conducting fluid, including substantially parallel members and connecting bends, two series of plates, each plate including a face-portion' and integral marginal fin-forming flanges for providing fins on the coil, the face-portions of the series of plates forming walls at the opposite sides of the coil, the flanges of each series being in abutting relation, and extended to the inner faces of the face-portions of the opposite series, the flanges having open-sided apertures, with constricted portions at the outer edges of the anges, the coil having a cross-sectional contour in tight- 'lli 1y gripped relation with the edges and interlocked with the edges of the constricted portions of the apertures, by which the plates are permanently secured on the coil, with the anges of each series in abutting relation, with the face-forming portions forming the walls and the fianges are secured to form ns on the coil.

5. A heat exchange unit, comprising a coil for conducting iiuid, including substantially parallel members and connecting bends, two series of plates, each plate including a face-portion and integral marginal fin-forming anges, the faceportions of the series of plates forming walls at the opposite sides of the coil and the flanges of each series being in abutting relation, and extended to inner faces of the face-portions of the opposite series, the coil having flat portions fitting the innerr faces of the plates, the flanges having open-sided apertures extending substantially across the flanges, with constricted portions at the outer edges of the flanges, the coil having a cross-sectional contour in tightly gripped relation with the edges and interlocked with the edges of the constricted portions of the apertures, by which the plates are permanently secured on the coil, with the face portions forming the walls, the flanges are secured to provide ns on the coil, and the flat portions of the coil are secured against the inner faces of the plates.

6. A heat exchange unit, comprising: a coil for conducting fluid and a series of plates provided with face-portions for forming a wall and integral marginal flanges having outer faces for abutting the anges of contiguous plates and constituting fins on the coil, the anges having apertures extending entirely across the anges with open sides at the edges of the flanges and with edges defining constricted portions, the coil having members extending through the apertures in abutting flanges and flat portions extending across and engaging the inner surfaces of the portions of the plates between the flanges and cross-sectionally contoured to fit the apertures and interlock with said constricted portions and secure the plates and coil in permanently assembled relation with the fiat portions of the coil in engagement with the inner surfaces of the portions of the plates between the flanges.

RICHARD W. KRITZER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,244,507 Knox Oct. 30, 1917 1,367,134 Hachmann Feb. 1, 1921 1,607,172 Sage Nov, 16, 1926 1,929,952 Limpert Oct. 10, 1933 2,050,993 Bush Aug. 1l, 1936 2,092,170 Kritzer Sept. 7, 1937 2,170,774 Fagan Aug. 22, 1939 2,217,702 Kleist Oct. 15, 1940 2,271,538 Brace Feb. 3, 1942 2,494,548 Goldberg Jan. 17, 1950 FOREIGN PATENTS Number Country Date 159,933 Great Britain Mar. 10, 1921 260,414 Great Britain Nov. 4, 1926 274,664 Great Britain July 28, 1927 449,483 Great Britain June 29, 1936 538,122 France June 3, 1922 

